Evaluation of the U.S. Air Force HEART program demonstration

The HEART program is being demonstrated on four Air Force bases to provide experience that will aid in making plans to extend the program Air Force-wide. Much of the experience will be preserved in the form of two major types of data. One type is the medical and biographical data from the participants, some of which is used in conducting the HEART program activities. The other type of data, relating to the performance of these activities, includes office records and results of some studies designed to furnish detailed information about some of the program activities. We outline plans for summarizing the data and presenting it in a form that will be useful to those who will plan the Air Force-wide program.     

FORUM: The U.S. Air Force HEART program model

The goal of the Health Evaluation and Risk Tabulation (HEART) Program is to reduce the incidence of cardiovascular disease in the U.S. Air Force. The program is midway through a demonstration phase operating at four Air Force bases in the United States. At each base, active-duty personnel are given a selective clinical screen to assess their risk of a cardiovascular incident in the next 8 years. At two of the four bases, intervention in the form of behavior modification, small-group treatment for smoking cessation and/or blood lipid/weight reduction is offered to volunteers who have been found at above-average risk. In addition, two bases (one with the intervention present and one with the intervention absent) have a basewide education component consisting of events and activities which teach specific techniques of CVD prevention.     

The U.S. Air Force HEART Program: The Air Force perspective

The U.S. Air Force Health Evaluation and Risk Tabulation (HEART) Program was initiated to design and test a preventive cardiology program for active-duty Air Force members. Most cardiovascular incidents in active-duty personnel occur at a career point which significantly magnifies their operational and fiscal effect as the bulk of events disable or kill personnel during their years of peak productivity. A registered nurse managed the program at each of the four demonstration bases. The number of medical technicians and health counselors varied according to base population. The program includes risk factor screening, risk ranking, basewide education, and focal group intervention for those at high risk. Screening consisted of a health and habits questionnaire, blood pressure measurement, serum glucose, serum total and HDL cholesterol, as well as serum thiocyanate and exhaled carbon monoxide. The total population screened at first screen was 12,000 and 8,000 are expected at second screen. It is likely that due to the military capability for long-term follow-up, primary prevention begun at the time of entry to active duty could effectively reduce the number of cardiovascular events experienced yearly in the Air Force. The final product of HEART will be a detailed plan for an Air Force-wide preventive cardiology plan.     

Distributional records from the U.S. Air Force ovitrapping program--1990.

During 1990, ovitrapping was conducted at 38 U.S. Air Force installations. Twelve installations were positive for Aedes albopictus. The August 24 collection of Ae. albopictus at Tinker Air Force Base, OK, is a first record for Oklahoma County. Four installations recorded the presence of Ae. aegypti; 14 installations were positive for Ae. triseriatus. During the previous 3 years, an increase in the distribution and abundance of Ae. albopictus coincided with a decline in Ae. aegypti.     

Distributional records from the U.S. Air Force ovitrapping program--1991.

During 1991, ovitrapping was conducted by 37 U.S. Air Force installations. Sixteen installations were positive for Aedes albopictus. The number (449) and percent (21.5%) of Ae. albopictus-positive ovipaddles was almost 4 times that of the previous year. The collections of Ae. albopictus at Columbus Air Force Base (AFB), MS, and Shaw AFB, SC, are new records for Lowndes and Sumter counties, respectively. Nine installations were positive for Ae. aegypti; 21 were positive for Ae. triseriatus.     

Analysis of Organophosphate Hydraulic Fluids in U.S. Air Force Base Soils

Tri-aryl and tri-alkyl organophosphates (TAPs) have been used extensively as flame-retardant hydraulic fluids and fluid additives in commercial and military aircraft. Up to 80% of the consumption of these fluids has been estimated to be lost to unrecovered leakage. Tri-aryl phosphate components of these fluids are resistant to volatilization and solubilization in water, thus, their primary environmental fate pathway is sorption to soils. Environmental audits of military air bases generally do not include quantification of these compounds in soils. We have determined the presence and extent of TAP contamination in soil samples from several U.S. Air Force bases. Soils were collected, extracted, and analyzed using GC/FPD and GC/MS. Tricresyl phosphate was the most frequently found TAP in soil, ranging from 0.02 to 130 ppm. Other TAPs in soils included triphenyl phosphate and isopropylated triphenyl phosphate. Observations are made regarding the distribution, typical concentrations, persistence, and need for further testing of TAPs in soils at military installations. Additionally, GC and mass spectral data for these TAPs are presented, along with methods for their extraction, sample clean-up, and quantification. Received: 22 July 1998/Accepted: 4 November 1998     

Exposures to 1,6-hexamethylene diisocyanate during polyurethane spray painting in the U.S. Air Force

1,6-Hexamethylene diisocyanate (HDI) exposures were measured during polyurethane enamel spray painting at four Air Force bases. Breathing zone samples were collected for HDI monomer and polyisocyanates (oligomers) using three sampling methods: NIOSH Method 5521, the Iso-Chek sampler, and the total aerosol mass method (TAMM). Exposures to HDI monomer are low when compared to current occupational exposure limits; the highest 8-hr time-weighted average (TWA) exposure found was 3.5 micrograms/m3, below the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 34 micrograms/m3. HDI oligomer levels were higher; mean task exposures indicated by either the Iso-Chek sampler or TAMM are above the Oregon ceiling limit of 1 mg/m3. Eight-hour TWA exposures, however, were much lower, with only one exceeding the Oregon standard of 0.5 mg/m3. Poor worker practices commonly observed during this study included: standing in downwind positions so paint overspray passed through breathing zones; spraying toward other painters; and using excessive paint spray gun air cap pressures. Workers should stand in upwind orientation relative to the aircraft being painted, causing overspray to move away from the painter's breathing zone; adjust their position to prevent spraying other painters or limit paint application to one worker at a time; and use air cap pressure gauges prior to spraying to limit spray gun air cap pressures and reduce paint overspray generation rates. These improved techniques will result in reduced worker exposures to isocyanates.     

Metal exposure among abrasive blasting workers at four U.S. Air Force facilities

Button Aerosol Samplers were used to monitor the personal exposure of workers performing abrasive blasting operations at four U.S. Air Force facilities. Inhalable aerosols containing 25 metals, including cadmium, lead, and chromium, were investigated. The Button Aerosol Sampler was chosen because of its ability to successfully withstand mechanical stress, prevent very large particles from collection, and protect the filter from overloading and shredding by rebound particles. In addition, previous studies have shown that the sampling efficiency of this personal Aerosol Sampler exhibits low sensitivity to the ambient air conditions and that it adequately follows the inhalability convention. Inductively coupled plasma (ICP) was used to analyze the collected samples for all 25 metals. In addition, visual absorption spectrophotometry (VAS) was used to analyze for hexavalent chromium because of the presence of strontium chromate. The collected samples yielded 8-hr time-weighted average (TWA) concentrations that were up to 250, 6, and 5 times higher than the permissible exposure limits (PELs) for cadmium, lead, and hexavalent chromium, respectively. Also, the chromium levels measured by the ICP and VAS exceeded the strontium chromate threshold limit value (TLV) by up to 640 and 950 times, respectively. No correlation was found between the ICP and VAS hexavalent chromium concentrations. The likely reasons of this were the presence of Cr (II) and (III) that cannot be detected by the VAS, and the chemical interference from iron and some other metals in the samples. The Button Aerosol Sampler was shown to be useful for the monitoring of workers' exposure to heavy metals during abrasive blasting operations.     

Establishing a physical criterion for assigning personnel to U.S. Air Force jobs

The Air Force has had problems with personnel being physically unable to perform the tasks within their assigned Air Force Specialty Code (AFSC). An assignment criterion was developed based on a single isoinertial strength score (X1): the incremental 1.83 m lift. The job assignment criterion was developed through three phases of work: Phase I analyzed AFSC tasks; Phase II developed strength/stamina tests; and Phase III established the assignment criteria.     

Predictors of low physical fitness in a cohort of active-duty U.S. Air Force members

BACKGROUND: Each branch of the U.S. armed forces has standards for physical fitness as well as programs for ensuring compliance with these standards. In the U.S. Air Force (USAF), physical fitness is assessed using submaximal cycle ergometry to estimate maximal oxygen uptake (VO2(max)). The purpose of this study was to identify the independent effects of demographic and behavioral factors on risk of failure to meet USAF fitness standards (hereafter called low fitness). METHODS: A retrospective cohort study (N=38,837) was conducted using self-reported health risk assessment data and cycle ergometry data from active-duty Air Force (ADAF) members. Poisson regression techniques were used to estimate the associations between the factors studied and low fitness. RESULTS: The factors studied had different effects depending on whether members passed or failed fitness testing in the previous year. All predictors had weaker effects among those with previous failure. Among those with a previous pass, demographic groups at increased risk were toward the upper end of the ADAF age distribution, senior enlisted men, and blacks. Overweight/obesity was the behavioral factor with the largest effect among men, with aerobic exercise frequency ranked second; among women, the order of these two factors was reversed. Cigarette smoking only had an adverse effect among men. For a hypothetical ADAF man who was sedentary, obese, and smoked, the results suggested that aggressive behavioral risk factor modification would produce a 77% relative decrease in risk of low fitness. CONCLUSIONS: Among ADAF members, both demographic and behavioral factors play important roles in physical fitness. Behavioral risk factors are prevalent and potentially modifiable. These data suggest that, depending on a member's risk factor profile, behavioral risk factor modification may produce impressive reductions in risk of low fitness among ADAF personnel.     

Costs of smoking among active duty U.S. Air Force personnel--United States, 1997

Smoking is the leading cause of preventable disease and death in the United States (1). The health consequences of smoking impose a substantial economic toll on persons, employers, and society. Smoking accounts for $50-$73 billion in annual medical-care expenditures, or 6%-12% of all U.S. medical costs (2-5). The costs associated with lost productivity also are extensive (2). In 1997, approximately 25% of male and 27% of female active duty Air Force (ADAF) personnel aged 17-64 years were smokers (6). A 1997 retrospective cohort study was conducted among ADAF personnel to estimate the short-term medical and lost productivity costs of current smoking to the U.S. Air Force (USAF). This report summarizes the results of the study, which indicate that current smoking costs the USAF approximately $107.2 million per year: $20 million from medical-care expenditures and $87 million from lost workdays.     

Exposures to jet fuel and benzene during aircraft fuel tank repair in the U.S. Air Force

Jet fuel and benzene vapor exposures were measured during aircraft fuel tank entry and repair at twelve U.S. Air Force bases. Breathing zone samples were collected on the fuel workers who performed the repair. In addition, instantaneous samples were taken at various points during the procedures with SUMMA canisters and subsequent analysis by mass spectrometry. The highest eight-hour time-weighted average (TWA) fuel exposure found was 1304 mg/m3; the highest 15-minute short-term exposure was 10,295 mg/m3. The results indicate workers who repair fuel tanks containing explosion suppression foam have a significantly higher exposure to jet fuel as compared to workers who repair tanks without foam (p < 0.001). It is assumed these elevations result from the tendency for fuel, absorbed by the foam, to volatilize during the foam removal process. Fuel tanks that allow flow-through ventilation during repair resulted in lower exposures compared to those tanks that have only one access port and, as a result, cannot be ventilated efficiently. The instantaneous sampling results confirm that benzene exposures occur during fuel tank repair; levels up to 49.1 mg/m3 were found inside the tanks during the repairs. As with jet fuel, these elevated benzene concentrations were more likely to occur in foamed tanks. The high temperatures associated with fuel tank repair, along with the requirement to wear vapor-permeable cotton coveralls for fire reasons, could result in an increase in the benzene body burden of tank entrants.     

Risk factors and recommendations for 230 adult primary care patients, based on U.S. Preventive Services Task Force guidelines.

We used a computer program based on the U.S. Preventive Services Task Force guidelines to identify recommendations for 230 adult patients who presented to an ambulatory family practice residency clinic. We entered risk factors into the computer program from sex-specific questionnaires that patients completed. On average, patients had 15.4 risk factors and 24.5 recommendations for preventive services (13.0 recommendations for screening, 10.5 for counseling, and 1.1 for immunizations). We noted a significant increase in the number of risk factors and recommendations with increasing age, except for counseling recommendations. The average patient incurs a large number of recommendations, which depend on many different risk factors, making the task of complete clinician compliance with the U.S. Preventive Services Task Force guidelines difficult. Many of these recommendations include counseling, which may take more time and require skills that clinicians may think they lack. Complete adherence may require several visits for the physician to address all recommendations. Measures to increase patient responsibility for health maintenance and innovations using comprehensive, interactive, and educational computer programs may help solve these problems.     

The impact of a change to inhalable occupational exposure limits: strontium chromate exposure in the U.S. Air Force

The American Conference of Governmental Industrial Hygienists has announced its intention to replace all total particulate threshold limit values (TLVs) with size-selective TLVs. Because the U.S. Air Force has adopted the TLVs as its occupational exposure limits, the impact of this change is of interest, specifically for hexavalent chromium. This article reviews historical strontium chromate sampling data in the Air Force and the impact of its reinterpretation in comparison to an inhalable TLV. Based on the measured conversion factor between the 37-mm cassette and the IOM inhalable sampler, inhalable strontium chromate exposures will continue to exceed the TLV during all aircraft priming and most sanding procedures. In addition, inhalable exposures are expected to exceed 1000 times the TLV, greater than the highest currently assigned protection factor for airline respirators, during 25% of priming procedures. Without a change in the value of the current TLV time-weighted average of 0.5 microg/m(3), the Air Force will need to reduce strontium chromate levels, either by incorporating work practices that decrease worker productivity or considering a change to nonchromated primers.